It’s been three years since our favourite demigod, Percy Jackson, prevented the destruction of Mount Olympus and it seems as if the last time was merely the beginning of young Percy’s career as the Gods' personal bodyguard.

The story picks up from where we left Percy (Logan Lerman) at Camp Half-Blood, the aptly named home of the hundreds of offspring of Gods and humans - these Olympians clearly like to procreate.

This time 'round, Percy is going through a personal crisis: was his last life-saving escapade merely a fluke or is he truly destined for greatness? Luckily, a chance for him to prove himself arises in the form of a quest to restore the barriers that protect Camp Half-Blood and his demigod cousins from destruction.

Standing in Percy’s way yet again is Luke (Jake Abel), the disgruntled son of Hermes who we encountered in Percy's last world-saving escapade. It seems that Luke is still dealing with his daddy issues and wants a second try at destroying the Gods of Olympus by raising the evil Titan lord, Kronos.

With their individual goals in mind, Luke and Percy are in a race to retrieve a mythical Golden Fleece - a piece of cloth with magical restorative powers - from the Sea of Monsters. Both are prepared to do anything to get it.

Based on the hugely successful Percy Jackson books by Rick Riordan, the film has some pretty interesting source material to draw from but unfortunately not even the unique mix of Greek mythology and reality can save Percy Jackson from being anything other than average.

What ultimately lets Percy Jackson down is the clichéd and often laughable characterisations. For example, the token bad-guy Luke seems to have taken all of his traits from Being Evil for Dummies, including ostentatious yacht, interest in creepy classical music and penchant for black, high-necked shirts.

Another problem is the dialogue. Every single conversation that takes place feels forced and unnatural, as if these characters are purely going through the motions, lacking any depth or believable feeling.

Despite these flaws, Percy Jackson does have some redeeming features, for example Percy's hapless half-brother, a Cyclops called Tyson (Douglas Smith), provides a welcome break from the more draining character interactions.

Similarly, Stanley Tucci (Mr D) has some amusing one-liners to work with and delivers them with his usual effortless flair. Had he been given more screen time, Tucci could have easily brought this film to a much more enjoyable place.

Like many films of this genre, it can be very easy to compare Percy Jackson with the fantasy heavyweight that is Harry Potter: both are films about unlikely heroes with two misfit best friends, absent parents and an evil blonde arch nemesis. But whereas the adventures of Mr Potter set the heart racing, poor Percy barely registers a pulse.